用竖式计算,后2题要验算438÷6= 678÷3= 408÷4=486×3= 780÷3 229÷9=
295÷0.25÷4.
9×99+99.
用简便方法计算.(1) (2)÷19+×(3)(1.6+1.6+1.6+1.6)×25 (4)9.25×9.9+92.5%
简便计算(1)9999+9998+9997+9996 (2)22222×999999(3)454十999×999十545 (4)20082008×2007﹣20072007×2008.
计算下面各题,怎样简便就怎样算.×0.25+0.375× 4.97+6.38+5.03﹣4.385.84×1.36+13.6×0.316+1.36 ﹣÷×0.5.